I thought I killed Wise Portia for sure when I gave it acidic water in February. The bush was green to the tip, then turned all black after I dumped that acidic water with used lemons, oranges, and grapefruits rinds.

Early May all stems are black, no green growth. Thank God I was too lazy to dig it up. In June I got one tiny green shoot. Now August 9, I have a full bush, much bigger than a gallon-size, it gave me 3 flushes with 10+ buds/blooms. My answer is less than 3 months, if the roots didn't get killed.

Last year, my husband mowed one of my teeny own roots from Rogue Valley - no, I didn't kill him - and it started regrowing in about a week; it got back to where it was before the unfortunate accident by the end of the summer.

Which is your question--

a) How old does a rose plant have to be, or how long planted, before it can survive the loss of all top growth? (No telling, would depend on conditions.)

b) How long does it take for new growth to appear from the roots? (Probably around 3-4 weeks.)

Thanks everybody, why I was wondering is because two ownroot roses I ordered from heirloom last fall, and two I ordered this spring the tops browned and died from that horrible 115 degree weather we were having, but they still seem to have some roots still(they were in the ground three months before they died). I put three of them before the died all the way in pots trying to save them( probably shouldn't have dug them up but..)and now two are still hanging on by like an inch of green top growth, but I don't know what to do. Leave them in pots and see if they come back or plant them back in ground around october after it's cooled. I've been keeping them watered. Should I give the roots/ pieces of stems any fish emulsion or just keep watering? With them being mostly roots with the little green I was thinking just water but not sure. Thanks for helping this noobie to ownroots.

JUST water! You have several issues...cooked plant from extreme heat which causes the heat trauma plus malnourishment from lack of photosynthesis. You have potential disturbed roots from transplanting. You have potentially greater heat stress from hot air surrounding the pots, plus any direct sun exposure to the pots heating up the soil ball and exacerbating the heat stress. Anything other than water you put on them could easily tip the balance and kill them off. Don't stress them out any more than they already are. Water, plain and simple. Try to shade the pots' sides to prevent them from over heating. Once you see new growth beginning, you may safely feed them your fertilizer of choice, but I would only do it at about half strength until the plants seem to have recovered. Kim

But don't overwater. Keep them moist but not flooded. Be sure the pots have good drainage. Roses can easily die of root rot from too much water. Water also leeches away nutrients in potted plants.

OK Thanks catrose and roseseek, I do have them in partly shaded area, when should I put them back in the soil? I was thinking october or november but wasn't sure on that.
THANKS YA'LL

Water and put the pots where they will get only morning sun or in all day dappled shade until they recover. You don't want any cane that's left to sunburn.

Thanks Seil thats pretty much what I did, hopefully, they will recover and I won't have to replace them :( . Although, I do have a pretty good size order coming along for the spring and everyone told me that teas, chinas, and noisettes, were best for my climate, and I went bananas over the chinas and am getting at least 10 maybe, more have to check, one noisette, and two tes, along with a couple others like rose de recht( had my eye on for a while)sounenir du dr jamain(I know not for my climate) and a couple other I just couldn't say no to. :) happy hardening to me hopefully and wish me luck!! :))